[americanLT1]

I think I've got a big problem.
Fired up my lt1 355 last week and after about 30 minutes of total run time the plugs are fouled with oil.
The engine has an aftermarket ecu for fuel management and I had a few issues with it when starting it. It ran quite rich and maybe that had something to do with it.
The rings are speed pro hell fire rings and the machine shop that bored and honed the block should have known what hone finish was required.
I have never had a problem with ring seat, but i have never used these rings or fooled with fuel injection.
Anyone have experience with this type of ring?
I think I'll be sick if I have to tear this motor down again.

 

[painted jester]

This 30 min of run time? does that include a cam break in or did you use the old cam and lifters? Is this fresh engine a complete rebuild or just a short block? it takes a lot longer to break in rings then 30 min. did you change oil after cam break in before driving ? Or are you still running the initial cam break in oil?


Plugs are known to fowl during break in!! That's not surprising especially on initial start ( oil is still in cylinders from assembly and insertion Of pistons and rings into cylinders) change plugs and oil and continue break in following normal break in driving procedures! after a few hundred miles of driving variable speeds the rings should be broke in and seated to the bore! If this is a race engine break in is completely different!

Jester

 

[americanLT1]

It's a fresh engine I assembled months ago and isn't a race motor but it is built with all forged lower end because it' turbocharged and that is why Diamond piston recommended these rings.
It also has a roller cam so no cam break in.
The engine is in a 59 rambler and don't quite have it to the point where it can be driven.
I'm used to rings that seat within minutes after starting but they were different compound, probably softer than these.

 

[CNC BLOCKS NE]

Do a leak down test at TDC as that will give you some idea what going on with ring seal.

I am not a fan of hell fire rings and on the forced inductions engines I have built the moly rings have worked out fine.

 

[americanLT1]

Did a leak down this morning, 8 to 10 %.
That's pretty bad.
Any chance these will seat if I can load the motor or is it to late?
I still have to get the injection worked out so it runs better

Thanks

 

[DoubleVision]

What oil did you use?

 

[ap72]

Did a leak down this morning, 8 to 10 %.
That's pretty bad.
Any chance these will seat if I can load the motor or is it to late?
I still have to get the injection worked out so it runs better

Thanks

You need to get your damn injection worked out first. Soaking those rings with fuel is not a good thing. After you get it tuned just drive the hell out of it for a few hours and your rings should start sealing.

You should be breaking it in with a good conventional oil, NOT SYNTHETIC. For the first few oil changes run a conventional oil. I like Valvoline in the plain white jug. After that you can switch to a good synthetic like Valvoline or Mobil 1.

 

[Mr. P-Body]

Those rings are going to need some real "pressure" to "seat". That is, you're going to have to drive it, dyno it, something... to put the engine under load. Good ring choice for a turbo application.

Agreed, fuel can KILL new rings. Ideally, use an SAE 30 ND oil for initial fire-up. We used to use that for everything "new", but flat-tappets can't anymore. Rollers are fine.

Jim

 

[americanLT1]

I used plain old valvoline 5-30 oil in it.
I know I need to get the injection worked out but easier said than done when your not familiar with it and I'm not having much luck getting qualified help
This is an older system and I guess they are not as user friendly
as some of the newer ones.
Also, It's kind of tough developing an accurate fuel map when your burning oil.
I've only built about a dozen motors and never had a ring problem with any of them but they were all motors with carbs.

Appreciate the input, this is a pain full problem after all the work and money I've invested in this motor.

 

[painted jester]

I used plain old valvoline 5-30 oil in it.
I know I need to get the injection worked out but easier said than done when your not familiar with it and I'm not having much luck getting qualified help
This is an older system and I guess they are not as user friendly
as some of the newer ones.
Also, It's kind of tough developing an accurate fuel map when your burning oil.
I've only built about a dozen motors and never had a ring problem with any of them but they were all motors with carbs.

Appreciate the input, this is a pain full problem after all the work and money I've invested in this motor.

With forged pistons it takes time for them to expand and reach operating temp! You can't start it cold and put it in gear and take off like cast pistons!!! and I would use a 10/30 or a straight 30 ND like the other gentleman suggested for break in ( but that's just me).
And your initial break in with rollers isn't just for the cam which I still run a break in for! Its also for break in on rockers to valve stems, timing chain, rings etc,It also flushes out impurity's From the assembly All your oil isn't filtering through your filter unless you blocked your oil bypass!!! As you drive oil is bypassing the filter at all times and only a percentage of flow is filtered! But you may already know that. That's why after your engines initial break in you change oil and filter before driving! Otherwise your pumping all that stuff your oil has washed out back through your engine!!!!

Detergent oil keeps impurity's suspended in the oil and non detergent lets them settle to the bottom of the pan so a lot of us older guys still use non detergent oil :mwink: If your not running cats run oil with good zinc content many parts of your eng still need it for protection ( any thing that makes metal to metal contact with pressure like a timeing chain wrist pins etc!


Jester

 

[CNC BLOCKS NE]

I have to aske was the block even plate honed?? If not I really don't eve see those rings seating to out of round cylinders !!!

I have seen circle track engines blow oil out the breathers so bad they need rags around them and after 3 years of racing the rings never sealed up.

I have sure fixed many of them over the years plate hone to the next bore size and the problem is solved.

 

[joelster]

What style of ecu is it? If you are unable to locate a tuner for it, try to do a few tiny tricks to lean it out a tad. If you have an adjustable regulator, back off the fuel pressure a tiny bit. Try a slightly hotter plug. You may have to unplug the o2's and keep it in open loop, because the closed loop tuning may want it at 12-1 or wherever it is set at. There won't be much you can really do until you get the tune squared away.

 

[cobalt327]

Ideally, use an SAE 30 ND oil for initial fire-up.

Same here, I have always used a good quality 30w for break in (I used detergent oil). I can't recall a ND oil having a decent API classification, although that doesn't mean there aren't any- just that I don't have ready access to any.

Since the oils have changed I have used Amzoil 30w break in oil, it's sold at the local O'Reilly's. Brad Penn/Howards Cams, Lucas, and Edelbrock's branded break in oils are also 30w.

But there are also those who sell multigrade break in oil. Royal Purple, Comp Cams is 10w-30. Gibbs is heaver (15w-50). I'm sure there are others. Plus all the guys who use over the counter multigrade motor oil w/ZDDPlus, etc. added.

I suppose at the end of the day it's more important to build the engine right and fire it up immediately after priming than to worry too much about the viscosity. But personally you'll not be seeing me use 10w-30/15w-40 for break in.

 

[americanLT1]

I checked the block before I assembled it and the bores were round and straight within about .0003.
The piston have about .0055 clearance.
The ecu is an old f.a.s.t. classic unit with wide band o2.

I just changed the plugs and made some changes to the spark map and it runs better. After about ten minutes I shut it down pulled a plug and checked the leak down again with the engine warm and got the same result about 8%.
The plug showed signs of oil again too.

I spent so much time building and detailing this motor I'ts going to be tough to tear it down again so soon.

I don't have the car at a point where it can be driven yet.
I wanted to make sure I had no issues with the motor before I install the front sheet metal.
Not so sure loading the motor will make a difference at this point in time.

Really frustrating because everything else looks so good, oil pressure. no leaks. and it runs super cool, considering its 110 in my garage.

Here's what it looks like.

 

[cobalt327]

I think I've got a big problem.
Fired up my lt1 355 last week and after about 30 minutes of total run time the plugs are fouled with oil.
The engine has an aftermarket ecu for fuel management and I had a few issues with it when starting it. It ran quite rich and maybe that had something to do with it.
The rings are speed pro hell fire rings and the machine shop that bored and honed the block should have known what hone finish was required.
I have never had a problem with ring seat, but i have never used these rings or fooled with fuel injection.
Anyone have experience with this type of ring?
I think I'll be sick if I have to tear this motor down again.

I just reread this and I see you're using Hellfire rings. You said "...the machine shop that bored and honed the block should have known what hone finish was required."

Don't take this the wrong way, but that is assuming a heck of a lot! If you didn't tell them/verify w/them to use 280 or whatever to finish the bores with, they might have used 400 for all you know (although this should have been apparent by eye when you were inspecting/assembling the block). I can tell you that if there's not enough "tooth" for those HF rings, they'll never break in before the bore has plateaued (knocked off all the peaks that break in the rings). IF that's the case, you might get away w/rehoning it, but that could play hell w/the piston to bore fit, depending on how much honing has to be done to achieve the correct finish.

 

[Guest]

did you apply oil to the piston sides and the rings when you installed them?

because alot of people coat the sides of the pistons including the rings and they have the same issue your describing.
which is a big no no.

only a little oil is required on the pin and skirts and i mean a little.

if you did oil them up real good and oil got onto the rings it will not let them seat and blow by will happen.

 

[painted jester]

did you apply oil to the piston sides and the rings when you installed them?

because alot of people coat the sides of the pistons including the rings and they have the same issue your describing.
which is a big no no.

only a little oil is required on the pin and skirts and i mean a little.

if you did oil them up real good and oil got onto the rings it will not let them seat and blow by will happen.

Ive seen guys dip their pistons and rings in a bucket of oil years ago one was Grumpy Jenkins, another was Garlets, among many others and through the years we learned it made a mess and you only needed a little lube on the rings and piston and a lite coat on the cylinder!!! :mwink: But I would never install piston rings dry or have dry ring lands! You do what you like but in 50 years of building Ive never had rings not seat or fail down the road!!! and that's in diesle, alchohol, race fuel, nitro , boats , aircraft etc etc. If all you guys install dry rings Ive been in the twilight zone !!! LOL

But do what your comfortable with and you know works:thumbup: And I wont enter into changing peoples minds!!!!!!!:mwink:

Jester

 

[americanLT1]

The machine shop that did the block builds a lot of race motors for boats and he had the pistons and rings so he knew what he was working with and the fact that it is a forced induction motor. But, like you say, It doesn't mean it was honed correctly.

I'm a bit worried about re-honing the block as the pistons already have over .005 clearance and that doesn't leave me with any good options. The pistons are custom so they are expensive and the block for this motor has been fitted with splayed caps, line bored and honed, decked and clearanced for the upgraded rod bolts so it's probably a wash as to which is cheaper.

I assembled this motor in February and all I did for lube on the rings and pistons is wipe them with a film of engine oil and same for the bores.
Then it sat for four months before it was started.

Thanks for the input.

 

[ap72]

Um... you have a turbo motor and your checking leak down when its cold? It should be high even if they seated your ring gaps are huge compared to na. Tune it the best you can then put some time on the engine. After an oil change or two then look at it. You're getting all worked up over nothing right now, plenty of engines have high leak down when assembled. Plenty of purpose built turbo engines have high leak down their entire life cycle and show no problems.

 

[CNC BLOCKS NE]

I checked the block before I assembled it and the bores were round and straight within about .0003.
The piston have about .0055 clearance.

With out a torque plate ir cylinder head bolted on the bores were that straight and round it was not plate honed thats for sure!!